S
M
T
W
T
F
S
30
97°
71°
31
98°
69°
1
99°
68°
2
98°
67°
3
96°
65°
4
94°
66°
5
93°
66°
6
94°
67°
7
95°
67°
8
97°
66°
9
94°
65°
10
94°
65°
11
93°
66°
12
93°
66°
13
96°
69°
14
98°
69°
15
99°
70°
16
99°
72°
17
98°
69°
18
99°
70°
19
98°
70°
20
99°
69°
21
96°
66°
22
95°
64°
23
91°
65°
24
93°
66°
25
97°
67°
26
88°
64°
27
91°
59°
28
Hist. Avg.
89°
61°
29
Hist. Avg.
89°
61°
30
Hist. Avg.
88°
61°
1
Hist. Avg.
88°
60°
2
Hist. Avg.
88°
60°
3
Hist. Avg.
87°
60°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Fort Irwin
Fort Irwin's September 2026 forecast shows daily high temperatures ranging from 88° to 99°, with overnight lows between 59° and 72°. The average high for September is 96° with an average low of 67°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Fort Irwin. See also: October | November | December.
